1. Field of the Invention
The apparatus of this invention is related to intravenous administration of medications and fluids and particularly to multiple administration of medications and fluids which have physio-chemical incompatibilities.
2. Description of the Prior Art
While vast forward steps have been made in recent years in the development of medications and fluids to be administered to patients, the mechanical art of administration has not kept pace with these scientific developments. The apparatus for administering such medications and fluids intraveneously in the patient, have led to a more or less standard type of infusion set which is comprised of a solution bottle having a stopper apertured for puncturing and venting, a spike or cap device which allows a tube to be connected to the bottle contents through puncturing the bottle stopper, the tube which connects the bottle to the needle, a drip chamber or indicator, and a means of flow control comprising a pinch clip or cock. When a plurality of fluids and medications are to be administered simultaneously, it has been necessary to use a separate needle, tubing and venipuncture for each solution, or to use one or more Y-tubes. Two, three and even four way stop cocks have been employed, and very frequently the flow from two or more fluids or medications, even though incompatible, have been combined and been given the opportunity to mix over a long time prior to entry into the body. Another system of administration is designed to permit the contents of two or more intravenous solution bottles to flow into a patient while all are connected together. Such a system allows an unlimited number of bottles to be connected in "series."
Today, fluids such as saline, dextrose and lactated fingers, to name a few, are administered by infusion using special equipment. The equipment is sterile, disposable and subject to stringent controls in the hospitals. An increasing hospital practice for the administration of medications is to combine them with such fluids. Many of these are life saving drugs and by their nature are administered intravenously quite often; in some cases, there is no other choice. Today, it is a very common practice for a physician to order three or more drugs to be administered simultaneously to the patient. Many of these drugs have chemical and physical incompatibilities and which is of special significance to the invention.
Numerous references are available concerning the critical problem of medication incompatibilities. The Norfolk General Hospital, Pharmacy Service, publication entitled "Intravenous Fluids, Incompatibility Guide" cites many such references and lists the following factors which may cause incompatibilities:
Preservative of Drug Oxidation Preservative in Diluent Reduction Buffering Agents Photosensitization Antioxidants Inactivation Vehicle Order of Mixing Changes in pH Period of Standing Molecular Complexation Brand of Drug Supersaturation Neutralization Change in Viscosity Precipitation Particle size distribution Improper Dilution ______________________________________
There are a number of ways to handle the incompatibility problem, all of which are presently unsatisfactory. The common method is to add one drug to the basic fluid in a burrett device and infuse it over an hour, then add the second drug, etc., thus consuming an inordinate amount of nursing time. Physicians and nurses are often concerned with such matters as the Ph of a fluid or its chemical and physical incompatibilities. The majority of incompatibilities are kinetically slow in developing, which necessitates the use of small volumes of basic infusion fluid as a diluent in a burrette device in contrast to placing all of the drugs to be administered in the 8 hour period in one large volume container. In many United States hospitals, the pharmacy has developed an intravenous (I.V.) fluid admixture service. The I.V. drugs are reconstituted and/or packaged aseptically in suitable small volume containers to be added by the nurse to existing I.V. infusions. Another practice is to actually prepare the large volume I.V. infusion which contains the drugs in labeled containers which are delivered to the nurse for subsequent administration. With the hospital pharmacist becoming more involved in intravenous admixture preparation and monitoring, the need for more accurate and dependable systems of delivery for incompatible medications is of paramount importance.